Electrical polar neutral relay



P. K. ECKH'ARDT ELECTRICAL POLAR NEUTRAL RELAY Dec. 14, 1943.

Filed March 21, 1942 Patented Dec. 14, 1943 ELECTRICAL POLAR NEUTRAL RELAY Paul K. Eckhardt, Sharpsburg, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania application Itiarch 21, 1942, Serial No. 435,743

Claims.

My invention relates to electrical relays, and particularly to direct current polar neutral relays.

One object of my invention is to provide a novel core structure for use in a relay of the type described to enable the relay to be more readily used as a plug-in relay.

Another object of my invention is the provision in a relay of the type described of novel means for preventing the neutral armature from closing unless the polar armature responds to reversals of the polarity of the current supplied to the main operating winding of the relay.

According to my invention, the relay comprises a magnetizable core provided at its ends with pole pieces which cooperate with a neutral armature. The one pole piece also cooperates with a polar armature which is pivotally sup ported intermediate its ends for swinging movement toward one or the other of two other pole pieces formed on permanent magnet means connected intermediate its ends with the core, said other pole pieces being of opposite polarity. The core is provided on opposite sides of said permanent magnet means with windings, one of which constitutes the main operating winding for the relay, and the other of which is energized over pole changing contacts operated by the polar armature and serves as a means for preventing the neutral armature from picking up unless the polar armature occupies a position corresponding to the polarity of the current supplied to said main operating winding. Said other winding is optional and may be omitted.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe one form of relay embodying my invention, and shall then point out the novel features thereof in claims.

The accompanying drawing is a view partly in isometric projection and partly diagrammatic showing one form of relay embodying my invention.

Referring to the drawing, the relay comprises a magnetizable core I which as here shown is in the shape of an inverted U with the ends of its legs turned inwardly to form two confronting pole pieces 2 and 3. Pole piece 3 is enlarged and is provided with a transverse channel 3a on its upper side and a longitudinal channel 32) on its lower side. Cooperating with core I is a neutral armature 4 which is pivotally mounted at 4a in the under channel 3b of pole piece 3 and which swings toward and away from pole piece 2. This (Cl. 32ll) armature is biased by gravity or otherwise to a position away from pole piece 2. Operatively connected with the neutral armature are a plurality of contact fingers I and 8 shown diagrammatically in the drawing. These fingers cooperate with fixed front contact members Ia and 3a or fixed back contact members 'Ib and 8b to close front contacts 'I'Ia and 8--8a or back contacts 'I"Ib and 8-82) according as the armature 4 is swung toward or away from the pole piece 2.

The pole piece 3 also cooperates with a polar armature 9 which, as here shown, lies in the upper channel 3a of the pole piece and is pivotally mounted at 9a therein for oscillation between two extreme positions. The armature 55 cooperates at its opposite ends with pole pieces 53 and I I formed on the lower ends of two permanent magnets 5 and 6, the upper ends of which are magnetically connected with the core 5. The pole pieces i9 and II are of opposite polarity, and if desired, these pole pieces, instead of being formed on two separate magnets 5 and 6, as shown, may be formed on a single magnet connected intermediate its ends to the backstrap, as is obvious. It should also be pointed out that while the armature 9 is shown pivotally attached directly to the pole piece 3, it could equally well be pivotally supported by means of a bracket secured to this pole piece or to some other part of the relay so long as the armature is in flux transfer relation with respect to the pole piece 3, as is also obvious. The polar armature is operatively connected with a plurality of contact fingers I2, 13 and I4 which cooperate with fixed normal contact members I2a, I35; and Ma, respectively, or with fixed reverse contact members I2b, I31) and Mb to close normal contacts I2I2a, I3-l3a and Id-Ida or reverse contacts I2-I2b, I3-I3b and l4l4b.

A winding I5 is provided on the core I between the pole piece 3 and the point where the permanent magnets are connected with the core. This winding constitutes the main energizing winding of the relay, and is arranged to be reversibly supplied with current from a suitable source of current here shown as a battery B over the contacts I6 and I! of a pole changer P.

A second winding I8 may also be provided on the core I between the pole piece 2 and the point where the permanent magnets are connected with the core. This winding is optional, and is only provided when it is desired to provide a check to insure that the neutral armature will not pick up unless the polar armature occupies a position corresponding to the polarity of the current supplied to the winding I5. The winding I8, when provided, may be energized from the same source of current as the winding I or from a different source over pole changing contacts controlled by the polar armature in such manner that the flux induced in core I by current flowing in winding I3 will aid that due to current flowing in winding I5 if the polar armature occupies a position corresponding to the polarity of the current supplied to winding IE, but will buck the flux induced in core I by current flowing in winding I5 if the polar armature occupies a position out of agreement with the polarity of the current supplied to winding I5. As shown in the drawing, winding I3 is connected with battery B over the polar contacts I2 and I3 connected as pole changing contacts. The parts are preferably so proportioned that when the flux due to winding i8 is bucking that due to winding it, the two fluxes set up in core I will neutralize each other.

As shown in the drawing, pole changer P is in its normal position so that current of what I shall term normal polarity is being supplied to winding I5. Polar armature 9 also occupies its normal position so that its normal contacts I2-I2a and I3I3a are closed, and under these conditions winding I8 is also supplied with current of normal polarity. With windings I5 and 18 both energized by current of normal polarity the fluxes set up in core I are additive, and the neutral armature 5 is therefore picked up so that front contacts 'Iia and 88a are closed and back contacts 7-42) and 8-fib are open.

I shall now assume that pole changer P is reversed, thereby reversing the polarity of the cur.- rent supplied to the winding I5. This causes the flux induced by the winding IE to buck that due to the winding I8, and armature t therefore releases. As soon as armature releases, the resulting large air gap between the armature and the pole piece 2 introduces a high reluctance in the portion of the magnetic circuit on which the winding is is disposed, and due to the current in winding It a high magnetic potential exists between the pole piece 3 and the point in the core I where the permanent magnets are connected with the core. Assuming that pole piece iii is a south magnetic pole and the pole piece II is a north magnetic pole, as indicated by the letters N and S in the drawing, the winding I5 is so arranged that the flux induced thereby with pole changer P reversed causes pole piece 3 to become a south pole, and as a result the polar armature 9 is now repelled from the pole piece It and attracted toward the pole piece II. The polar armature therefore reverses and opens its normal contacts and closes its reverse contacts. This causes winding 58 to be supplied with current or" reverse polarity, and since the fluxes due to the windings I5 and iii are again additive, the neutral armature 4 picks up.

When pole changer P is restored to the position shown, the operation is similar to that just described, except for the fact that under these conditions the pole piece 3 becomes a north pole so that the polar armature 9 is repelled from pole piece El and is attracted toward pole piece it. The parts therefore return to the positions in which they are shown in the drawing.

As was pointed out hereinbeiore, the winding i8 is optional, and is only provided to insure that the neutral armature will not pick up when the supply of current to winding I5 is reversed unless the polar armature reverses; When this winding I8 is omitted, the relay operates as a straight polar neutral relay. In this case, when the polarity of the current supplied to winding I 5 is reversed, the flux in core I will pass through zero, which will cause armature i to release. The polar armature will then reverse and armature A will subsequently pick up, these operations taking place without any cheer; 0n the polar armature position.

Although I have herein shown and described only one form of relay embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. A polar relay comprising a magnetizable core provided at its ends with pole pieces, a winding on said core, a neutral armature associated with said pole pieces and responsive to the presence or absence of current in said winding, permanent magnet means provided at its opposite ends with pole pieces or opposite polarity and connected intermediate its ends with said core between said winding and one of the pole pieces on said core, and a polar armature pivotally supported intermediate its ends for swinging movement toward one or the other of the pole pieces on said permanent magnet means, said polar armature being magnetically associated with the other pole piece on said core.

2. A polar relay comprising a magnetizable core provided at its ends with pole pieces, permanent magnet means connected with said core intermediate its ends and provided at its ends with pole pieces of opposite polarity, a winding on said core between one of said pole pieces and the point where said permanent magnet means is connected with said core, a neutral armature pivotally attached to said one pole piece for swinging movement toward and away from the other pole piece on said core and biased by gravityto swing away from said other pole piece, and a polar armature pivotally attached intermediate its ends to said one pole piece for swinging movement toward one or the other of the pol pieces on said permanent magnet means.

3. A polar relay comprising a magnetizable core provided at its ends with pole pieces, permanent magnet means connected with said core intermediate its ends and provided at its ends with pole pieces or" opposite polarity, a winding on said core between one of said pole pieces and the point where said permanent magnet means is connected with said core, a neutral armature pivotally attached to said one pole piece for swinging movement toward and away from the other pole piece on said core and biased by gravity to swing awa from said other pole piece, a polar armature pivotally attached intermedi ate its ends to said one pole piece for swinging movement toward one or the other of the pole pieces on said permanent magnet means, and means for preventing said neutral armature from closing unless said polar armature occupies a position corresponding to the polarity of the current supplied to said winding, said means comprising a second winding disposed on said core between the point where said permanent magnet means is connected with the core and the other pole piece on said core.

4. A polar relay comprising a m-agnetizable core provided at its ends with pol pieces, permanent magnet means connected with said core intermediate its ends and provided at its ends with pole pieces of opposite polarity, a winding on said core between one of said pole pieces and the point where said permanent magnet mean is connected with said core, a neutral armatur pivotally attached to said one pole piece for swinging movement toward and away from th other pole piece on said core and biased by gravity to swing away from said other pole piece, a polar armature pivotally attached intermediate its ends to said one pole piece for swinging movement toward one or the other of the pole pieces on said permanent magnet means, and means for preventing said neutral armature from closing unless said polar armature occupies a position corresponding to the polarity of the current supplied to said winding, said means comprising a second winding disposed on said core between the point Where said permanent magnet means is connected with the core and the other pole piece on said core and energized over pole changing contacts controlled by the polar armature in such manner that when both windings are energized they will set up additive fluxe in the core if and only if said polar armature occupies a position corresponding to the polarity of the current supplied to said first mentioned winding.

5. In combination, a magnetizable core provided at its ends with pole pieces, permanent magnet means connected with said core and provided at its ends with pole pieces, a first winding on said core between one of the associated pole pieces and thepoint where said permanent magnet means is connected with said core, means for reversibly supplying said first Winding with current, a neutral armature associated with the pole pieces on said core and responsive to the presence or absence of current in said first winding, a polar armature pivotally supported intermediate its ends for swinging movement toward one or the other of the pole pieces on said permanent magnet means, said polar armature being magnetically associated with said one pole piece on said core, whereby it is responsive to the polarity of the current supplied to said first winding, and means for preventing said neutral armature from closing unless said polar armature occupies a position corresponding to the polarity of the current supplied to said first winding comprising a second winding on said core between the other associated pole piece and the point where said permanent magnet means connects with said core, and means for supplying said second winding with current over pole changing contacts controlled by said polar armature in such manner that the fluxes induced in said core by said two windings will be additive if and only if said polar armature occupies a position corresponding to the polarity of the current supplied to said first winding.

PAUL K. ECKHARDT 

